Method of making a conductive filler

ABSTRACT

A method for producing an electrically conductive filler by placing a web of core material onto an interior surface of a web of conductive layer material. The webs of core material and conductive layer material are directed through a forming station for folding the conductive layer around the core. The filler having a substantially non-conductive core and a conductive layer. The conductive layer is wrapped around the core to form a closed loop thereby establishing conductivity from a bottom of the filler to a top of the filler by paths on each of two sides of the filler.

This application claims the benefit of U.S. Provisional Application No.60/112,957, filed Dec. 18, 1998 and non-provisional application Ser. No.09/458,489 filed Dec. 9, 1999.

BACKGROUND OF THE INVENTION

The present invention generally relates to a conductive filler and amethod of making the filler. The filler is adapted for use in electricalcoils, such as Roebel windings as a Roebel filler to fill intersticesbetween the windings and a casing wall. The filler of the presentinvention is also useful in other applications where a flexible and/orcompressible conductive material is needed. For example, the presentfiller can be used in the construction of an electrically shieldedcabinet.

Various techniques for filling voids between parts in electricallyconductive devices are known. Unfortunately, many prior art techniquesdo not succeed in completely filling the voids and/or suppressingelectrical discharge across the voids. Many void fillers act as adielectric and allow a voltage to be impressed across the filler.Failure to fill the voids or at least suppress discharge will result inundesirable arcing between the components. Arcing leads to diminishedefficiency and diminished life expectancy of the device.

An example of a conductive device where voids are present is a highvoltage coil havipg windings that are intertwined in a braid-likefashion to form a Roebel bar. Roebel bars, or Roebelled windings, have ahighly discontinuous surface. This surface has a great number of voids,or interstices, which must be properly filled in order to reducemechanical and electrical stresses. U.S. Pat. No. 5,175,396 dated Dec.29, 1992 to Emery, incorporated herein by reference, discloses such aRoebel bar. The U.S. Pat. No. 5,175,396 discloses a prior art voidfiller made from Dacron felt impregnated with epoxy. The U.S. Pat. No.5,175,396 is directed to providing a void filler made from an insulatinglayer of mica paper and B stage epoxy. A semiconductive layer,preferably a paste of carbon filled epoxy, is placed between the innerinsulating layer and a groundwall.

Other filler materials have been used to fill voids in electrical coils.Discussion of a resin rich felt material may be found in U.S. Pat. No.5,633,477 dated May 27, 1997 to Smith. Discussion of an inert fillermaterial and a pyrolyzed glass fiber layer electrically coupled to thestrands of a coil may be found in U.S. Pat. No. 5,066,881 to Elton.These fillers, and other prior art fillers and pre-pegs, are oftendifficult to install in high voltage coils and/or are not suitableforuse in other applications, such as in the construction of anelectrically shielded cabinet.

SUMMARY OF THE INVENTION

The present invention overcomes these disadvantages by providing anelectrically conductive filler, the filler having a substantiallynon-conductive core and a conductive layer. The conductive layer iswrapped around the core to form a closed loop thereby establishingconductivity from a bottom of the filler to a top of the filler by pathson each of two sides of the filler.

According to another aspect of the invention, the conductive layer iswrapped around the core such that the top of the filler is provided withtwo laminations of the conductive layer.

The present invention provides a method of making a web of conductivefiller by placing a web of core material onto an interior surface of aweb of conductive layer material. The webs of core material andconductive layer material are directed through a forming station. Theforming station turns first and second edges of the conductive layermaterial upward, folds the first edge of the conductive layer materialover the core material, and folds the second edge of the conductivelayer material over the first edge of conductive layer material.

BRIEF DESCRIPTION OF THE DRAWING

These and further features of the present invention will be apparentwith reference to the following description and drawings, wherein:

FIG. 1A is an end view of a conductive filler according to a firstembodiment of the present invention.

FIG. 1B is an end view of a conductive filler according to a secondembodiment of the present 5 invention.

FIG. 2 is a perspective view of the conductive filler, according toeither embodiment, shown in an intermediate stage of assembly.

FIG. 3 is a perspective view of a Roebel winding having the conductivefiller of the second embodiment.

FIG. 4 is a schematic of an assembly line for producing the conductivefiller according to either embodiment of the present invention.

FIGS. 5A to 5F are schematic views showing various stages of productionfor the conductive filler according to the present invention.

FIG. 6 is a perspective view of a forming station according to thepresent invention.

DESCRIPTION OF THE INVENTION

In the detailed description which follows, identical components havebeen given the same reference numerals, regardless of whether they areshown in different embodiments of the present invention. In order toclearly and concisely illustrate the present invention, the drawings maynot necessarily be to scale and certain features may be shown insomewhat schematic form.

Referring to FIGS. 1A, 1B, 2 and 3, the present invention provides aconductive filler 10. The conductive filler 10 is adapted to fill voidsin electrical devices. For example, the filler 10 can be used to fillvoids, or interstices 12, created between transposed conductor windings14 and a groundwall, or casing wall 16, of an electric coil 18 (FIG. 3).A coil 16 of this nature is commonly referred to as a Roebel bar.Additional discussion of Roebel bars is contained in U.S. Pat. No.5,175,396 dated Dec. 29, 1992 to Emery, incorporated herein byreference. The filler 10 is preferably conductive to suppress electricaldischarges. To fill as much of the voids as possible, the filler 10 ispreferably compressible. Two lengths of filler 10 are preferably used ineach bar, one length being disposed on top of the conductor windings 14and the other disposed below. Alternatively, additional lengths can beprovided along the sides of the winding stacks. In another alternative,lengths of filler 10 can be wrapped around the windings 14.

The filler 10 is preferably conductive, flexible and compressible. Thesequalities make the filler 10 effective to fill interstices 12 ofdifferent shapes and sizes. The conductive properties of the filler 10prevents voltage from being impressed across an otherwise dielectricfiller. If the filler 10 were not conductive, voltage would appearacross the filler 10 and undesirable electrical discharges would occur.Accordingly, the filler 10 is well suited for use in Roebel bars andinapplications other than electric coils. For example, the filler can beplaced between the panels of an electrically shielded cabinet.

The filler 10 provides a core 20. The core 20 is preferablynon-conductive. The core 20 is preferably a felt-like, non-wovenmaterial, such as a polyester felt or aramid fiber batts, such as NOMEX.Preferably, the core 20 weighs about 9 ounces per square yard.Preferably, the core 20 is resin rich. More specifically, the core 20 ispreferably impregnated with an epoxy, such as bis-a. The epoxy assiststhe filler 10 in conforming to and staying in the interstices 12 foundin a Roebel bar. The core 20 is preferably 50% to 90% loaded with epoxy,more preferably 65% to 85% loaded and most preferably about 80% loaded.A suitable core 20 material is available from Lectromat, Inc., P.O. Box608, 18 Mars, Pa., 16046.

The filler 10 also provides a conductive fleece, or conductive layer 22,which is wrapped completely around the core 20 to form a closed looparound the core 20. The conductive layer 22 has an interior side 24disposed towards the core 20 and an exterior side 26 disposed away fromthe core 20. The conductive layer 22 is preferably made from polyesterfibers which are themselves not conductive. The fibers are preferablyimpregnated with a resin containing a conductive substance, such ascarbon. The fibers of the conductive layer 22 are loaded with resin sothat the conductive layer 22 has a resistance of about 200 f2 persquare. Depending on the application for the filler 10, the resistanceper square can be widely varied such as 10 to 1,000,000 0 per square.However, for use in an electric coil 18, a resistance of 200 i2 persquare will provide sufficient conduction between the casing 16 and thewindings 14 to suppress corona discharge. Suitable material for theconductive layer 22 is available from Isovolta in Vienna, Austria underthe name CONTAFEL-H 0865.

The conductive layer 22 is preferably wrapped completely around the core20 as best illustrated in FIGS. 1A and 1B. Since the conductive layer 22is wrapped completely around the core 20 to form a closed loop,conductivity is established from a bottom of the filler 10 to a top ofthe filler 10 by paths on both sides of the filler 10. A firstembodiment of the filler 10 is illustrated in FIG. 1A. In the firstembodiment, the conductive layer 22 is wrapped completely around thecore 20 with a small portion of the conductive layer 22 overlappingitself.

A second embodiment of the filler 10 is illustrated in FIG. 2A. In thesecond embodiment, the conductive layer 22 is wrapped completely aroundthe core 20 with a large portion of the conductive layer 22 overlappingitself. More specifically, the conductive layer 22 is layered on a top28 of the core 20 such that a first edge 30 of the conductive layer 22is generally aligned with a first edge 32 of the core 20. The conductivelayer 22 wraps around a second edge 34 of the core 20, a bottom 36 ofthe core 20 and the first edge 32 of the core 20. The conductive layer22 continues to wrap around the core 20 such that the conductive layer22 is layered on top of itself. A second edge 38 of the conductive layer22 is generally aligned with the second edge 34 of the core 20. As oneskilled in the art will appreciate, the fillers 10 of the first andsecond embodiment are essentially the same, but the conductive layer 22of the second embodiment is wider than the conductive layer 22 of thefirst embodiment such that the conductive layer 22 of the secondembodiment overlaps itself more than that of the first embodiment.

To show additional features of both embodiments of the filler 10, FIG. 2shows the core 20 placed on the interior side 24 of the conductivefiller 22 in-an intermediate stage of assembly. The assembly processwill be described in more detail below. To establish adhesion of theconductive layer 22 to the core 20, the filler 10 is preferably providedwith a first layer of pressure sensitive adhesive 40 and a second layerof pressure sensitive adhesive 42. The first and second layers ofadhesive 40, 42 are preferably strips of transfer adhesive made from anacrylic with a polyester carrier. The first and second adhesive layers40, 42 are preferably about 0.25 millimeters thick.

As best illustrated in FIG. 2, the first strip of adhesive 40 isdisposed on the interior side 24 of the conductive layer 22 adjacent afirst edge 30 of the conductive layer 22. The second strip of adhesive22 is disposed on the interior side 24 of the conductive layer 22adjacent a second edge 38 of the conductive layer 22.

As illustrated in FIG. 1A for the first embodiment of the filler 10,when the conductive layer 22 is wrapped around the core 20, the firstadhesive layer 40 preferably secures the area adjacent the first edge 30of the interior surface 24 of the conductive layer 22 to the top 28 ofthe core 20. The second adhesive layer 42 preferably secures the areaadjacent the second edge 38 of the interior surface 24 of the conductivelayer 22 to the exterior surface 26 of conductive layer 22 adjacent thefirst edge 30, or to both the exterior surface 26 of the conductivelayer 22 adjacent the first edge 30 and the top 28 of the core 20 asillustrated. In this way, the conductive layer 22 slightly overlapsitself and is, at a minimum, wrapped completely around the core 20. Asone skilled in the art will appreciate, the conductive layer 22 may besecured to and wrapped around the core 20 in other ways. For instance,the conductive layer 22 may be wrapped only partially around the core20.

It is advantageous to wrap the conductive layer 22 completely around thecore 20 so that there is electrical conductivity between the top and thebottom of the filler 10. It is desirable to provide this electricalconductivity along both sides of the filler 10 because, in somesituations, a corner of the filler 10 may be shaved to size the filler10 for use in a particular application. If the corner is shaved, ordamaged, a disconnect in the electrical conductivity will result in theshaved area. However, the conductivity between the top and the bottom ofthe filler 10 will not fail since the other side of the filler 10 willremain electrically conductive.

As illustrated in FIG. 1B for the second embodiment of the filler 10,when the conductive layer 22 is wrapped around the core 20, the firstadhesive layer 40 preferably secures the area adjacent the first edge 30of the interior surface 24 of the conductive layer 22 to the top 28 ofthe core 20 adjacent the first edge 32 of the core 20. The secondadhesive layer 42 preferably secures the area adjacent the second edge38 of the interior surface 24 of the conductive layer 22 to the exteriorsurface 26 of the conductive layer 22 adjacent the second edge 34 of thecore 20.

The second embodiment of the conductive filler 10 is the preferredembodiment for use in a Roebel bar. This is because the resin from thecore 20 can raise the resistance of the conductive layer 22. To keep theresistance at a desirable level it is preferable to have two laminationsof the conductive layer 22 on at least one side of the filler 10. Thisside of the filler 10 is preferably placed toward the windings 14 of theRoebel bar as illustrated in FIG. 3. Alternatively, the filler 10 of thefirst embodiment can be used with or without other means of maintainingthe conductive layer's resistance. Other potential solutions includemodifying the filler 10 of the first embodiment. Example modificationsinclude lowering the initial resistance of the conductive layer 22,modifying the thickness of the conductive layer 22, or reducing theamount of resin in the core 20.

To assist placement of the filler 10 in coils 18, cabinets and the like,the exterior surface 26 of the conductive layer 22 is preferablyprovided with an outer adhesive layer 44. The outer adhesive layer 44 ispreferably the same type of adhesive as the first and second inneradhesive layers 40, 42, but is also provided with a release liner 46.The release liner 46 prevents the filler 10 from adhering to itself whenthe filler 10 is rolled for storage and packaging, and protects theunderlying adhesive layer 44 until the release liner 46 is removed. Theouter adhesive layer 44 can be provided on virtually any location on theouter surface 26 of the conductive layer 22. For most applications, theouter adhesive layer 44 need only provide enough adhesion to temporarilyhold the filler 10 in place until the apparatus in which the filler 10is being used is fully assembled and the filler 10 cannot be easilymoved out of place under normal operating conditions.

For use in electrical coils 18isuch as Roebel bars, the outer adhesivelayer 44 is preferably placed in the center of one side of the filler10. In the second embodiment, the adhesive layer 44 is placed on theside of the filler 10 having the overlapping layers, or two laminations,of conductive layer 22 as illustrated in FIG. 1B. This allows the fillerto be secured to the conductor windings with the overlapping layers 22of conductive layer adjacent the conductor windings 14 as illustrated inFIG. 3.

Tests of the filler 10 according to the second embodiment of the presentinvention were conducted. The tests were conducted under IEEE Standard286(1975), titled “IEEE Recommended Practice for Measurement ofPower-factor Tip-Up of Rotating Machinery Stator Coil Insulation,”incorporated herein by reference. Under IEEE Std. 286, the power factor,and resultant Tip-Up value, of four 2, OkV production style Roebel barsas illustrated in FIG. 3 were measured. Two of the test bars containedfiller 10 according to the second embodiment. The other two barscontained non-conductive fillers made from aramids, more specifically aresin rich B-stage aramid and a polyester felt without resin. A lowTip-Up value represents an efficient coil. Preferably, the Tip-Up valueis less than 1%. The coils containing the filler 10 according to thesecond embodiment had very desirable Tip-Up values of 0.48% and 0.51%respectively. The test results also indicate that there is a highrepeatability in the performance of the bars using the filler 10. Thebar containing a B-stage aramid filler has a Tip-Up value of 1.13%. Thebar containing a resin free polyesterfelt has a Tip-Up of 2.570. Thefollowing chart shows the power factor, in percent, for each bar atvarious test voltages.

Power Factor (Tan Delta (%)) Filler #1 Filler #2 Filler #4 (With (WithFiller #3 (Polyester Test Conductive Conductive (B-stage Felt; VoltageLayer 10; Tip- Layer 10; Tip- aramid; Tip- Tip-Up of (kVrms) Up of0.51%) Up of 0.48%) Up of 1.13%) 2.57%)  3.3 0.96 0.94 1.20 1.16  6.61.24 1.23 1.38 1.68  9.9 1.40 1.33 1.80 2.75 13.2 1.47 1.42 2.33 3.7516.5 1.57 1.56 2.97 4.51 19.6 1.67 1.66 3.46 5.10

FIGS. 4, 5A to 5F, and 6 illustrate a device and a preferred method ofproducing the conductive filler 10 of the present invention. As bestshown in FIGS. 4 and 5A, a first unwind station 60 is provided with asupply roll 62 of a web of conductive layer 22 of the conductivematerial 64 for forming the conductive layer 22 of the conductive fill10. It is noted that throughout the method of producing the conductivefiller 10 that tensioning rollers are used as needed. Some of therollers are illustrated but not discussed herein.

The web of conductive layer material 64 is directed to a second unwindstation 66 provided with a pair of supply rolls 68 of webs of adhesive.A first supply roll 68 a of adhesive provides a web of adhesive layermaterial 70 a for the first adhesive layer 40 and a second supply roll68 b of adhesive provides a web of adhesive layer material 70 b for thesecond adhesive layer 42. The webs of adhesive material 70 a, 70 b onthe supply rolls 68 a, 68 b are each provided with a suitable releaseliner 72 a, 72 b. The webs of adhesive layer material 70 a, 70 b, alongwith their release liners 72 a, 72 b are unwound and respectivelypositioned on the interior surface 24 of the web of conductive layermaterial 64 along the first edge 30 and second edge 38 of the conductivelayer 22. The webs of conductive layer material 64, adhesive layermaterial 70 a, 70 b and release liners 72 a, 72 b pass through a pair ofpressure or pinch rollers 74 which apply pressure to secure the web ofconductive layer material 64 and webs of adhesive 70 a, 70 b together.The release liners 72 a, 72 b are then removed from the webs of firstand second adhesive layer material 70 a, 70 b by, a suitable linercollector 76. The liners 72 a, 72 b can be advantageously removed andcollected by a vacuum device. The filler 10 at this stage of productionis best illustrated in FIG. 5b and is made of the web of conductivelayer material 64 provided with the webs of first and second adhesivelayer material 70 a, 70 b respectively placed along the first edge 30and second edge 38 of the conductive layer 22.

The web of conductive layer material 64 and the webs of adhesive layermaterial 70 a, 70 b are directed to a third unwind station 78. The thirdunwind station 78 is provided with a supply roll 80 of a web of corematerial 82. The web of core material 82 is unwound and positioned ontothe interior surface of the web of conductor layer material 64 betweenthe first and second edges 30, 38 of the web of conductive-layermaterial 64 and between the webs of first and second adhesive layermaterial 70 a, 70 b as best illustrated in FIG. 5C.

The web of core material 82, webs of adhesive layer material 70 a, 70 band the web of conductive layer material 64 are directed to a formingstation 86. As best shown in FIGS. 4, 5D and 6, the forming station 86folds the web of conductive layer material 64 around the web of corematerial 82 by upwardly bending, or folding, the first and second edges30, 38 of the web of conductive layer material 64.

The forming station 86 further wraps the web of conductive layermaterial 64 around the web of core material 82 so that the first edge,30 of the web of conductive layer material 64 is wrapped onto the topsurface 28 of the web of core material 82 and the second edge 38 of theweb of conductive layer material 82 is wrapped onto the web ofconductive layer material 82, as illustrated in FIG. 5E. Wrapped in thismanner, the web of conductive layer material 64 is now wrappedcompletely around the web of core material 82. It is noted that thefolds in the web of conductive layer material 64 are started by hand,but, once started, the rest of the web of conductive layer material 64is folded automatically. It is noted however that the entire folding, orcuffing, process can be automated using suitable tooling.

Referring to FIG. 6, the forming station 86 provides a die 88 defining a“U-shaped” channel, or passageway 90, a roller 92, a base 94 and aseries of posts 96. The webs of conductive layer material 64, adhesivelayer material 70 a, 70 b, and core layer material 82 pass through theU-shaped passageway 90. The portions of the web of conductive layermaterial 64 that are to be folded onto the top 28 of the web of corematerial 82 are bent upward and pass through respective leg portions ofthe passageway 90. The web of core material 82 and the remaining portionof the web of conductive layer material 64 pass through a base of thepassageway 90. To help prevent snagging and tearing of web the corematerial 82 and the web of conductive layer material 64, the die 88 canoptionally be lined with a piece of low friction guide material 98surrounding the passageway 90. After the webs 64, 70 a, 70 b, 82 passthrough the passageway g0, the web of conductive layer material 64 has aU-shaped cross section matching the shape of the passageway 90 and theportion of the exterior surface 26 of the web of conductive layermaterial 64 that forms the bottom of the liner 10 slides along the base94. The web of core material 82 is weighted downward and held inposition by the roller 92 by trapping the web of core material 82 andthe web of conductive layer material 64 between the roller 92 and thebase 94. The roller 92 is allowed to rotate about an axis on an axle 100supported by stanchions 102. The circumference of the roller 92 may alsobe provided with a low friction material. Optionally, the circumferenceof the roller 92 may have a concave or convex profile to shape the webof core 10 material 82.

After the webs 64, 82 pass under the roller, the upwardly turnedportions of the web of conductive layer material 64 are wrappedcompletely around the web of core material 82. This is accomplished bybending the first edge 30 of the web of conductive layer material 64toward the first edge 32 of the web of core material 82 and subsequentlybending the second edge 38 of the web of conductive layer material 64over the first edge 32 of the web of conductive layer material 64 andtoward the second edge 34 of the web of core material 82. This wrappingprocess is carried out by the series of posts 96. Preferably, the posts96 are securely mounted in the base 94. A first set of progressivelybent posts 104 direct the first edge 30 of the web of conductive layermaterial 64 over the web of core material 82 towards the first edge 32of the web of core material 64 to form a first, or inner, conductorlayer lamination 106 (FIG. 5E) disposed on the top 28 of the web of corematerial 82. Afirst set of guide posts 108 are disposed on theoppositeside of the web of partially formed filler material from thefirst set of progressively bent posts 104 to help the web of partiallyformed filler material continue to travel in a linear fashion. A secondset of progressively bent posts 110 are located on the opposite side ofthe partially formed filler from the first set of progressively bentposts 104 but down stream from the first set of guide posts 108. Thesecond set of progressively bent posts 110 direct the second edge 38 ofthe web of conductive layer material 64 over the inner conductor layerlamination 106 to form a second, or outer, conductor layer lamination112 (FIG. 5E) on the exterior surface 26 of the inner conductor layerlamination 106. A second set of guide posts 114 are disposed on theopposite side of the web of partiallyformed filler material from thesecond set of progressively bent posts 110 to help the web of partiallyformed filler material continue to travel in a linear fashion. Oneskilled in the art will appreciate that the wrapping need not be carriedout by posts or finger like projections as illustrated, but can becarried out by other types of barriers that are arranged to direct theconductive layer into position, such as by strips of sheet metal.

Referring to FIG. 4, the web of core material 82 and the now wrapped webof conductive layer material 64 are directed to a forth unwind station120. The forth unwind station 120 is provided with a supply roll 122 ofa web of adhesive and liner material 124 for forming the outer adhesivelayer 44 and the release liner 46. As best shown in FIGS. 4 and 5F, theweb of adhesive and liner material 124 is directed onto the top externalsurface of the web of conductive layer material 64 where it is centrallypositioned. The assembled filler 10 is then directed to a pair ofpressure or pinch rollers 126. The pinch rollers 126 apply pressure toset the webs of adhesive material 70 a, 70 b and supply sufficientpressure to secure the web of adhesive and liner material 124 to the webof conductive layer material 64, thereby forming a completed web 128 ofconductive filler 10. The completed web 128 of the conductive filler 10is then directed to a rewind station 130 were it is wound into a roll132, preferably around a cardboard or plastic sleeve. Once rolled, theconductive filler 10 can be packaged and shipped. The rolled fillerstock can be unwound and used in the production of electric coils,shielded cabinets and the like.

The rewind station 130 is provided with a first take up roller 134 and asecond take up roller 136. Each take up roller 134, 136 is preferablyprovided with a clutch. Once a predetermined length of completed web 128is wound on the first take up roller 134, e.g., 225 inches, the clutchstops rotation of the roller 134. The completed web 128 may then be cutand positioned for winding on the second take up roller 136. Rotationalmovement of the second take up roller 136 is stopped by its clutch aftera predetermined length of completed web 128 is wound thereon. Thecompleted web 128 is then cut and moved to the first take up roller 134and the foregoing process is 5 repeated.

Although particular embodiments of the invention have been described indetail, it will be understood that the invention is not limitedcorrespondingly in scope, but includes all changes and modificationscoming within the spirit and terms of the claims appended hereto.

What is claimed is:
 1. A method of making a web of conductive filler,comprising the steps of: placing a web of core material onto an interiorsurface of a web of conductive layer material comprising fibers whereinsubstantially all the fibers are non-conductive; and turning first andsecond edges of the conductive layer material upward, folding the firstedge of the conductive layer material over the core material, andfolding the second edge of the conductive layer material over the firstedge of conductive layer material.
 2. The method according to claim 1,further comprising the step of placing a web of adhesive layer materialonto the interior surface of the web of conductive layer material. 3.The method according to claim 2 wherein said web of conductive layerincludes the substantially non-conductive fiber impregnated with aconductive resin.
 4. The method according to claim 1, further comprisingthe step of placing a web of adhesive layer material onto the interiorof the web of conductive layer material.
 5. The method according toclaim 1 wherein said web of conductive layer includes the substantiallynon-conductive fiber impregnated with a conductive resin.
 6. A methodfor making a conductive filler material comprising the steps of:selecting a web of conductive layer material comprising fibers whereinsubstantially all the fibers are non-conductive said web of conductivelayer material having an interior surface and an exterior surface;positioning a web of non-conducting core material onto said interiorsurface of said web of conductive layer material; folding said web ofconductive layer material around said web of non-conducting corematerial, wherein said web of conductive layer material is completelywrapped around said web of non-conducting core material; and pressingsaid web of non-conducting core material wrapped with said web ofconductive layer material by passing through a pair of rollers to formsaid conductive filler.
 7. The method according to claim 6, wherein saidweb of conductive layer material includes substantially non-conductivefiber impregnated with a conductive resin.
 8. The method according toclaim 7, wherein said web of conductive layer material is folded aroundsaid web of non-conducting core material such that said web ofconductive layer material overlaps itself on one side of said web ofnon-conducting core material, thereby forming a laminated layer of saidweb of conductive layer material.
 9. The method according to claim 6,wherein said web of conductive layer material is folded around said webof non-conducting core material such that said web of conductive layermaterial overlaps itself on one side of said web of non-conducting corematerial, thereby forming a laminated layer of said web of conductivelayer material.
 10. A method for making a conductive filler material ina continuous process comprising the steps of: selecting a web ofconductive material, said web of conductive material having an interiorsurface and an exterior surface, with said interior surface including afirst edge and a second edge; selecting a first adhesive web; selectinga second adhesive web; positioning said first adhesive web on said firstedge of said web of conductive material; positioning said secondadhesive web on said second edge of said web of conductive material;selecting a web of a non-conducting core material; positioning said webof non-conducting core material onto said interior surface of said webof conductive material between said first and said second adhesive webs;folding said web of conductive material with said first and said secondadhesive webs thereon around said web of non-conducting core material,wherein said web of conductive material is completely wrapped aroundsaid web of non-conducting core material; and pressing said web ofconductive material with said first and said second adhesive websthereon folded around said web of non-conducting core material bypassing through a pair of rollers to form said conductive filler. 11.The method according to claim 10, wherein said web of conductivematerial includes substantially non-conductive fiber impregnated with aconductive resin.
 12. The method according to claim 11, wherein said webof conductive material is folded around said web of non-conducting coresuch that said web of conductive material overlaps itself on one side ofsaid web of non-conducting core material, and further wherein one ofsaid first and said second adhesive webs is against a top surface ofsaid web of non-conducting core material and the other of said first andsaid second adhesive webs is against said exterior surface of said webof conductive material, thereby forming a conductive filler having alaminated layer of said conductive material.
 13. The method for making aconductive filler material of claim 10, wherein said web of conductivematerial is folded around said web of non-conducting core such that saidweb of conductive material overlaps itself on one side of said web ofnon-conducting core, and further wherein one of said first and saidsecond adhesive webs is against a top surface of said web ofnon-conducting core material and the other of said first and said secondadhesive webs is against said exterior surface of said web of conductivematerial, thereby forming a conductive filler having a laminated layerof said conductive material.
 14. A method for making a conductive fillermaterial comprising the steps of: selecting a web of conductivematerial, said conductive material including a substantiallynon-conductive fiber impregnated with a conductive resin; said web ofconductive material having an interior surface and an exterior surface;selecting a first adhesive web having a first side and a second side,said first side of said first adhesive web covered by a first releaseliner, selecting a second adhesive web having a first side and a secondside, said first side of said second adhesive web covered by a secondrelease liner; positioning said first adhesive web covered by said firstrelease liner on said first edge of said web of conductive material,wherein said second side of said first adhesive web is in contact withsaid interior surface of said web of conductive material; positioningsaid second adhesive web covered by said second release liner on saidsecond edge of said web of conductive material, wherein said second sideof said second adhesive web is in contact with said interior surface ofsaid web of conductive material; pressing to secure said first adhesiveweb and said second adhesive web to said web of conductive material,wherein said pressing is done by passing said web of conductive materialwith said adhesive webs thereon through a first pair of rollers;removing said first release liner from said first adhesive web; removingsaid second release liner from said second adhesive web; selecting a webof non-conducting core material including non-woven fibers impregnatedwith a resin; positioning said web of non-conducting core material ontosaid interior surface of said web of conductive material between saidfirst and said second adhesive webs; folding said web of conductivematerial with said first and said second adhesive webs thereon aroundsaid web of non-conducting core material at a forming station byupwardly bending or folding said web of conductive material to form anunfinished filler; and pressing said unfinished filler by passing saidunfinished filler through said second pair of rollers, whereinsufficient pressure is applied by said pressing to secure said secondside of said outer adhesive web to said center portion of said topsurface of said unfinished filler, thereby forming said conductivefiller.
 15. The method for making a conductive filler material of claim14, wherein said web of conductive material is folded around said web ofnon-conducting core such that one of said first and said second adhesivewebs is against a surface of said web of non-conducting core materialand the other of said first and said second adhesive webs is againstsaid exterior surface of said web of conductive material, said bendingor folding forming a laminated layer of said web of conductive material,wherein said web of conductive material is completely wrapped aroundsaid web of non-conducting core material, thereby forming saidunfinished filler having said laminated layer of said conductivematerial, said method thereby resulting in a conductive filler havingsaid laminated layer of said conductive material.
 16. The methodaccording to claim 14, further comprising the steps of: selecting anouter adhesive web having a first side and a second side, said firstside of said outer adhesive web covered by an outer release liner; anddirecting said outer adhesive web with said outer release liner onto acenter portion of said top surface of said unfinished filler, and thencompleting the step directing said unfinished filler toward said secondpair of rollers.
 17. The method for making a conductive filler materialof claim 14, wherein said web of conductive material is folded aroundsaid web of non-conducting core such that one of said first and saidsecond adhesive webs is against a top surface of said web ofnon-conducting core material and the other of said first and said secondadhesive webs is against said exterior surface of said web of conductivematerial, said bending or folding forming a laminated layer of said webof conductive material, wherein said web of conductive material iscompletely wrapped around said web of non-conducting core material,thereby forming the unfinished filler with a top surface having withsaid laminated layer of said conductive material, said method therebyresulting in a conductive filler with a top surface having saidlaminated layer of said conductive material.
 18. A method for making aconductive filler material comprising the steps of: feeding a web ofconductive material from a roll of said web of conductive material at afirst unwind station, said conductive material including substantiallynon-conductive fiber impregnated with a conductive resin; said web ofconductive material having an interior surface and an exterior surface,with said interior surface including a first edge and a second edge;directing said web of conductive material to a second unwind stationhaving a first and a second roll of adhesive material, wherein saidfirst roll of adhesive material includes a first adhesive web having afirst side and a second side, said first side of said first adhesive webcovered by a first release liner, and further wherein said second rollof adhesive material includes a second adhesive web having a first sideand a second side, said first side of said second adhesive web coveredby a second release liner; unwinding and positioning said first adhesiveweb covered by said first release liner on said first edge of said webof conductive material, wherein said second side of said first adhesiveweb is in contact with said interior surface of said web of conductivematerial; unwinding and positioning said second adhesive web covered bysaid second release liner on said second edge of said web of conductivematerial, wherein said second side of said second adhesive web is incontact with said interior surface of said web of conductive material;directing said web of conductive material with both said first adhesiveweb with said first release liner and said second adhesive web with saidsecond release liner thereon toward a first pair of rollers; pressing tosecure said first adhesive web and said second adhesive web to said webof conductive material, wherein said pressing is done by passing saidweb of conductive material with said adhesive webs thereon through saidfirst pair of rollers; removing said first release liner from said firstadhesive web by using a first liner collector; removing said secondrelease liner from said second adhesive web by using one of said firstliner collector and a second liner collector; directing said web ofconductive material with both said first and said second adhesive websthereon to a third unwind station containing a roll of a web of anon-conducting core material, said web of non-conducting core materialincluding non-woven fibers impregnated with a resin; feeding andpositioning said web of non-conducting core material onto said interiorsurface of said web of conductive material between said first and saidsecond adhesive webs; directing said web of conductive material withboth said first and said second adhesive webs thereon and also with saidweb of non-conducting core material thereon, to a forming station;folding said web of conductive material with said first and said secondadhesive webs thereon around said web of non-conducting core material byupwardly bending or folding said web of conductive material, wherein oneof said first and said second adhesive webs is against a top surface ofsaid web of non-conducting core material and the other of said first andsaid second adhesive webs is against said exterior surface of said webof conductive material, said bending or folding forming a laminatedlayer of said web of conductive material, wherein said web of conductivematerial is completely wrapped around said web of non-conducting corematerial, thereby forming an unfinished filler with a top surface havingsaid laminated layer of said conductive material; directing saidunfinished filler toward a second pair of rollers; and pressing saidunfinished filler by passing said unfinished filler through said secondpair of rollers, wherein sufficient pressure is applied by said pressingto secure said second side of said outer adhesive web to said centerportion of said top surface of said unfinished filler, thereby formingsaid conductive filler.
 19. The method according to claim 18, furthercomprising the steps of: before directing said unfinished filler towardsaid second pair of rollers, directing said unfinished filler materialtoward a fourth unwind station containing a third roll of adhesivematerial containing an outer adhesive web having a first side and asecond side, said first side of said outer adhesive web covered by anouter release liner; and unwinding and directing said outer adhesive webwith said outer release liner onto a center portion of said top surfaceof said unfinished filler, and then completing the step directing saidunfinished filler toward said second pair of rollers.
 20. The methodaccording to claim 19, further comprising the steps of: directing saidconductive filler toward a rewind station; and winding said conductivefiller onto a rewind roll using said rewind station, wherein saidconductive filler can then be packaged and shipped to a destination. 21.A method for making a conductive bar comprising the steps of: selectinga web of conductive material, said conductive material including asubstantially non-conductive fibers impregnated with a conductive resin;said web of conductive material having an interior surface and anexterior surface, said interior surface including a first edge and asecond edge; selecting a first adhesive web having a first side and asecond side, said first side of said first adhesive web covered by afirst release liner; selecting a second adhesive web having a first sideand a second side, said first side of said second adhesive web coveredby a second release liner; positioning said first adhesive web coveredby said first release liner on said first edge of said web of conductivematerial, wherein said second side of said first adhesive web is incontact with said interior surface of said web of conductive material;positioning said second adhesive web covered by said second releaseliner on said second edge of said web of conductive material, whereinsaid second side of said second adhesive web is in contact with saidinterior surface of said web of conductive material; pressing to securesaid first adhesive web and said second adhesive web to said web ofconductive material, wherein said pressing is done by passing said webof conductive material with said adhesive webs thereon through a firstpair of rollers; removing said first release liner from said firstadhesive web; removing said second release liner from said secondadhesive web; selecting a web of a non-conducting core material, saidweb of non-conducting core material including non-woven fibersimpregnated with a resin; positioning said web of non-conducting corematerial onto said interior surface of said web of conductive materialbetween said first and said second adhesive webs; folding said web ofconductive material with both said first and said second adhesive websthereon around said web of non-conducting core material at a formingstation by upwardly bending or folding said web of conductive material,wherein one of said first and said second adhesive webs is against asurface of said web of non-conducting core material and the other ofsaid first and said second adhesive webs is against said exteriorsurface of said web of conductive material, said bending or foldingforming a laminated layer of said web of conductive material, whereinsaid web of conductive material is completely wrapped around said web ofnon-conducting core material, thereby forming an unfinished fillerhaving said laminated layer of said conductive material; selecting anouter adhesive web having a first side and a second side, said firstside of said outer adhesive web covered by an outer release liner;directing said outer adhesive web with said outer release liner onto acenter portion of said top surface of said unfinished filler; pressingsaid unfinished filler by passing said unfinished filler through asecond pair of rollers, wherein sufficient pressure is applied by saidpressing to secure said second side of said outer adhesive web to saidcenter portion of said top surface of said unfinished filler, therebyforming said conductive filler; placing said conductive filler at a topand a bottom of a stack of windings; wrapping an insulating groundwallaround said conductive filler with said stack of windings; and formingsaid conductive bar by sealing said insulating groundwall.
 22. A methodof making a conductive filler, comprising the steps of: wrapping a webof conductive material comprising fibers wherein substantially all thefibers are non-conductive impregnated with a conductive resin around acore material, wherein an adhesive is between and in contact with atleast a portion of the core material and the web of conductive material;and pressing said web of conductive material wrapped around said web ofcore material to form said conductive filler.